<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title></title>
    <script>
      let str = '1.txt';

      if(str.startsWith('.txt')){
        alert('');
      }else if(str.startsWith('.jpg')){
        alert('');
      }else if(str.startsWith('.png')){
        alert('');
      }else if(str.startsWith('svn://')){
        alert('');
      }else {
        alert('');
      }

    </script>
  </head>
  <body>

  </body>
</html>
